Long-term follow-up of Ethibloc injection in aneurysmal bone cysts.

The aim of this study is to assess the long-term results of Ethibloc injection in aneurysmal bone cysts (ABC). Thirty-three patients with ABC were treated with computed tomography-guided percutaneous injection of Ethibloc into the cyst cavity. Twenty-two patients had Ethibloc injection as primary treatment and 11 patients had presented to us with recurrence after previous procedures including steroid injection, bone marrow injection, curettage bone grafting and various other surgical procedures. The mean follow-up was 54 (22-90) months. Symptoms were relieved in all patients. Two patients were lost to follow-up. Eighteen (58%) of the 31 patients followed, had complete resolution of the lesion, 11 (35.5%) patients had partial healing (asymptomatic residual nonprogressive lytic areas). Two (6.5%) patients showed recurrence in the proximal humerus during the follow-up. They are under follow-up but asymptomatic and another two patients encountered more significant complications after the procedure. Ethibloc injection is a relatively simple, minimally invasive alternative procedure for the treatment of ABC, and makes open operation unnecessary by stopping the expansion of the cyst and inducing endosteal new bone formation. This technique may be used as the primary management of ABC's excluding spinal lesions as shown by our largest and longest follow-up study.